Sealed rotary table

ABSTRACT

A motion control apparatus in the form of a sealed rotary table ( 10 ) includes a first annular seal ( 54 ) located between a bearing cap ( 48 ) of a case and an inner diameter of a cylindrical flange ( 60 ), and a second annular seal ( 56 ) located between a seal ledge ( 22 ) of an annular wall ( 18 ) of the case and the outer diameter of the cylindrical flange ( 60 ). An enclosure ( 24 ), the annular wall ( 18 ) and a planar annular disc ( 16 ) are integrally formed as a single piece part of homogenous material. A drive station ( 12 ) includes a rotor ( 110 ) rotatably mounted inside an annular sleeve ( 118 ) by a bearing ( 140 ) inside an annular end cap ( 136 ) at an axial extent less than that of the annular sleeve ( 118 ). An encoder ( 150 ) is located within the annular end cap ( 136 ) and within the axial extent of the annular sleeve ( 118 ).

BACKGROUND

A motion control apparatus, particularly, a rotary motion controlapparatus, and, specifically, a sealed rotary table are shown anddescribed.

With the introduction of ring drives into the market place, there is acontinuing need for motion control apparatus which is modular in designto provide flexibility in application, as well as being stronger andeasier to manufacture.

SUMMARY

This need and other problems in the field of motion control apparatusare solved by providing a sealed rotary table including a bearingrotatably mounting an output to a case about an axis and within anannular wall of the case, and a drive station mounted to the case androtating the output. The output includes a cylindrical flange havingouter and inner diameters, with a first annular seal located between thecase and the inner diameter of the output, and with a second annularseal located between the annular wall of the case and the outer diameterof the output.

In further aspects, a case, including a planar annular disc and theannular wall extending axially from the planar annular disc, furtherincludes an enclosure having a panel integrally connected to the annularwall and extending radially outward opposite to the output, a topintegrally formed with the panel, and a lower opening defined by thepanel. The panel, the top and the lower opening have cross sectionsperpendicular to the axis which are U-shaped. The annular wall includesa side opening corresponding to the enclosure, with the planar annulardisc including an arcuate cutout corresponding to the enclosure and theside opening, and with the planar annular disc, the annular wall and theenclosure being integrally formed as a single piece part.

In a still further aspect, a drive station includes a housing includingan annular end and an annular sleeve extending parallel to the axis fromthe annular end and terminating in a sleeve end at a sleeve axial extentfrom the annular end. A rotor is rotatably mounted inside the annularsleeve and terminating in a rotor axial extent from the annular end,with the rotor axial extent being less than the sleeve axial extent. Anannular end cap is secured to the sleeve end. A rotor bearing rotatablymounts the rotor inside the annular end cap at a bearing axial extentfrom the annular end less than the sleeve axial extent and generallyequal to or less than the rotor axial extent. An encoder, received inthe annular end cap, has an inner axial extent less than the sleeveaxial extent, with the encoder rotationally related to the rotor. Amotor is located concentrically to the rotor and between the annular endand the annular end cap and within the annular sleeve, with the annularend and the annular sleeve integrally formed as a single unitary piece.

Illustrative embodiments will become clearer in light of the followingdetailed description in connection with the drawings.

DESCRIPTION OF THE DRAWINGS

The illustrative embodiments may best be described by reference to theaccompanying drawings where:

FIG. 1 shows an exploded perspective view of a sealed rotary table.

FIG. 2 shows a perspective view of a component of the sealed rotarytable of FIG. 1.

FIG. 3 shows a sectional view of the sealed rotary table of FIG. 1.

FIG. 4 shows a bottom perspective view of the component of the sealedrotary table of FIG. 2.

All figures are drawn for ease of explanation of the basic teachingsonly; the extensions of the figures with respect to number, position,relationship, and dimensions of the parts to form the illustrativeembodiments will be explained or will be within the skill of the artafter the following description has been read and understood. Further,the exact dimensions and dimensional proportions to conform to specificforce, weight, strength, and similar requirements will likewise bewithin the skill of the art after the following description has beenread and understood.

Where used in the various figures of the drawings, the same numeralsdesignate the same or similar parts. Furthermore, when the terms “top”,“bottom”, “first”, “second”, “forward”, “rearward”, “reverse”, “front”,“back”, “height”, “width”, “length”, “end”, “side”, “horizontal”,“vertical”, “axial”, “radial”, “longitudinal”, “lateral”, and similarterms are used herein, it should be understood that these terms havereference only to the structure shown in the drawings as it would appearto a person viewing the drawings and are utilized only to facilitatedescribing the illustrative embodiments.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

A sealed rotary table is shown in the drawings and generally designated10. Rotary table 10 generally includes a drive station 12 and a platform14. Platform 14 includes a planar annular disc 16 having an annular wall18 extending axially from annular disc 16 located concentrically withinan outer periphery of annular disc 16 to define a mounting flange 20located radially outward of annular wall 18. A seal ledge 22 is locatedat the free end of annular wall 18. Platform 14 further includes anenclosure 24 including a top 26 generally of a U-shape parallel toannular disc 16 integrally connected to annular wall 18 and extendingradially outwardly opposite to seal ledge 22. Enclosure 24 furtherincludes a U-shaped panel 28 integrally extending axially from the outerperiphery of top 26, integrally extending from annular wall 18, andterminating in a flange 30 integrally connected to mounting flange 20and extending radially outward of panel 28. The free edge of panel 28opposite to top 26 defines a lower opening. An opening 32 is formed inannular wall 18 corresponding to enclosure 24, and annular disc 16includes an arcuate cutout 34 corresponding to enclosure 24 and opening32. Annular disc 16 further includes an annular protrusion 36 extendingfrom its top surface concentrically around a center opening 38 andextending axially from annular disc 16 in the same direction as annularwall 18. Annular disc 16 also includes first and second channels 80extending radially from center opening 38 to the outer periphery ofmounting flange 20. Annular disc 16, annular wall 18, annular protrusion36 and enclosure 24 are integrally formed as a single, inseparableelement formed of homogenous material and define a case.

Platform 14 further includes an annular output 40 including an outerdriven gear 42. A bearing 44 has an inner race 46 abutting with annularprotrusion 36 and sandwiched against annular disc 16 by a bearing cap 48mounted to protrusion 36, with bearing 44 rotatably mounting output 40to the case about an axis and within the case. Bearing cap 48 hasgenerally L-shaped cross sections and includes an axially extendingportion and a radially extending portion extending radially onwardly ofthe axially extending portion. An O-ring 84 is provided in a cavityformed in a lower surface of the free end of the axially extendingportion of bearing cap 48 abutting with an upper annular free end ofannular protrusion 36 and is in sealing engagement with the inner axialsurface of inner race 46. Race 46 abuts with the axially extendingportion of bearing cap 48 and with annular protrusion 36. Outer race 50of bearing 44 is connected to annular output 40 such as by fasteners 52extending through race 50 and suitably secured to output 40 such as bythreading and extending parallel to the rotation axis of output 40. Anannular seal 54 is supported upon outer race 50 and extends between theannular free end of the radially extending portion of bearing cap 48 andoutput 40, and an annular seal 56 is supported upon seal ledge 22 andextends between annular wall 18 and output 40.

The normal intent of output 40 is to alter the speed and torque ofanother adjacent or meshed part/assembly. Bearing 44 is used to providelow friction rotation between a mounting surface 58 and outer drivengear 42. It should be appreciated that output 40 in rotary table 10 hasmultiple functionalities. Output 40 includes a cylindrical flange 60, alocating pilot, mounting surface 58, and mounting holes 62 providing alarge open center and for attaching componentry. Outer driven gear 42 isparallel to, intermediate, and spaced from planar annular disc 16 andcylindrical flange 60, with outer drive gear 42 having a radial extentoutward of cylindrical flange 60. Mounting holes 62 extend axially froma top surface of cylindrical flange 60 and radially intermediate theinner and outer diameters of cylindrical flange 60. The outer and innerdiameters of cylindrical flange 60 also act as sealing surfaces forseals 56 and 54 to inhibit contamination from reaching internally.Output 40 further includes an annular pilot recess 82 on a lower surfacethereof for locating outer race 50 and for attachment by fasteners 52extending parallel to the rotation axis of output 40 and extendingthrough race 50 and suitably secured to output 40 such as by threading.The shape of output 40 supports all of these functions while acceptingthe required meshing geometry of a mating pinion 100.

Output 40 is a single, inseparable element formed of homogeneousmaterial to provide increased stiffness between driven torque providedby output 40 and the added componentry, improving servo controllabilityand predictability. Further, improved manufacturing stack ups isprovided between bearing rotation, user output connection, and geartooth variability. Optimized machining of gear tooth variation about thebearing center rotation improves the overall accuracy specifications.Added componentry spinning true to the bearing's center of rotationminimizes rotational error and vibration in applications. Further, asingle piece part with all of the capabilities listed above reduces costand assembly time, thus improving manufacturability.

Similarly, platform 14 provides multiple functionalities. Protrusion 36provides increased rigidity and supports and captures bearing 44.Annular wall 18 provides increased rigidity, internally shields rotarytable 10 from the outside environment and includes seal ledge 22.Radially extended, top-enclosed enclosure 24 encapsulates the drivestation 12 of rotary table 10 providing additional stiffness to combatthe reaction loads of dynamic movements to resist deflection fromreaction forces between driven gear 42 and pinion 100 while shieldingdrive station 12 from the outside environment. An open slot 66 locatedin the bottom of enclosure 24, opening 32, and arcuate cutout 34 providefull disengagement and re-engagement of drive station 12 for assemblyand maintenance purposes. Open slot 66 is surrounded by mounting holes68 for attaching drive station 12. Mounting flange 20 provides mountingholes 70 for installation in the user's application, and channels 80provide a route for wiring, tubing or the like to pass from centeropening 38 past the periphery of mounting flange 20 on the user'sapplication.

Likewise, the bearing cap 48 captures bearing 44 through the use offasteners 72 threaded into mounting holes 64 in protrusion 36. The outerdiameter of bearing cap 48 also acts as a sealing surface for seal 54.Radial holes can be provided in bearing cap 48 to provide access to thecentral bearing's greasing holes.

Pinion 100 is of the type of U.S. Pat. No. 6,023,989, which isincorporated herein by reference, and includes rollers 102circumferentially arranged to be supported by a pair of annular plates104. Each of rollers 102 of pinion 100 is rotationally supported betweenthe pair of annular plates 104 by bearings 106 received in sockets inthe pair of annular plates 104. Rollers 102 are positioned in parallelwith each other at regular intervals in the circumferential directionand between the pair of annular plates 104 and are adapted to meshconcurrently with corresponding teeth of driver gear 42.

Pinion 100 is suitably connected to a rotor 110, in the form shown asbeing a stub shaft. In the form shown, pinion 100 is connected to rotor110 by having rotor 110 and the pair of annular plates 104 integrallyformed as a single, inseparable element formed of homogeneous material.

Generally, drive station 12 includes a housing 114 mounted to the caseand rotating output 40, with housing 114 having an annular end 116. Anannular sleeve 118 extends axially from annular end 116 parallel to therotation axis of output 40 and of rotor 110 to define a mounting flange120 located radially outward of annular end 116. A plurality of mountingholes 122 is formed in mounting flange 120 to receive fasteners 124threadably received in mounting holes 68 and extending parallel to therotation axis of output 40 and of rotor 110. Mounting holes 122 arenon-circular and have a cross sectional size larger than the crosssectional size of fasteners 124. Mounting flange 120 and mounting holes122 mount drive station 12, such that the axis of rotation of pinion 100and rotor 110 is off center in order to accommodate different pinion andgear meshing diameters, providing flexibility and product modularity.Further, in order to achieve proper mesh of drive gear 42 and pinion100, pinion 100 and rotor 110 must be preloaded into driven gear 42. Itshould be appreciated that the larger cross section of mounting holes122 allows drive station 12 to be mounted with fasteners 124 in anuntightened fashion, the drive station 12 to be preloaded, and thenfasteners 124 are tightly fastened to fix drive station 12 in thepreloaded position. Furthermore, slot 66, opening 32 and cutout 34provide full disengagement and re-engagement of drive station 12 formodularity in assembly and maintenance purposes.

A bearing 126 is sandwiched between a radially inwardly extending flange128 formed inside annular end 116 and a radially outwardly extendingshoulder 130 formed on the lower annular plate 104. A seal 132 issupported upon a radially inwardly extending shoulder formed insideannular end 116 and extends between the annular end 116 and an axialsurface of rotor 110 to seal drive station 12 from the environment.

Drive station 12 further includes an annular end cap 136 of a steppedfrustoconical shape and a preload cap 138 removably connected to an endof rotor 110. End cap 136 is secured to the annular end of sleeve 118such as by fasteners extending through end cap 136 and secured to sleeve118, such as by being threaded. A bearing 140 is sandwiched betweenpreload cap 138 and a radially extending inner flange of annular end cap136. Bearing 140 is sandwiched between rotor 110 and an inner axialopening formed in annular end 116 and between a shoulder defined onrotor 110 and a flange extending radially inwardly from the inner axialopening of annular end 116. Bearing 140 is at an axial extent B fromannular end 116 less than the axial extent S of sleeve 118 and generallyequal to or less than the axial extent R of rotor 110. Thus, rotor 110is rotatably supported and preloaded between bearings 126 and 140 indrive station 12.

An encoder 150 is received in an axial cavity formed in annular end cap136 and includes a frustoconical protrusion 152 extending throughpreload cap 138 and into a corresponding bore formed in the end of rotor110. The inner axial extent E of encoder 150 is less than axial extent Sof sleeve 118. Encoder 150 is rotatably related to rotor 110. Rotarytable 10 includes a motor located concentrically to rotor 110 and havinga first motor component 160, such as windings, secured to housing 114 bysuitable provisions such as adhesive and extends from annular end 116 toan axial extent Ml less than annular sleeve 118 but greater than rotor110. A second motor component 162, such as permanent magnets, is securedto rotor 110 by suitable provisions such as fasteners threadly receivedin an axial end of lower annular plate 104. The second motor component162 has an axial extent 1′12 less than axial extent Ml of first motorcomponent 160, a first end axially spaced from annular end 116 and asecond end generally at the same axial extent as rotor 110 from annularend 116.

It should be appreciated that rotor 110 and the pair of annular plates104 formed as a single, inseparable element creates a high stiffness andallows rotor 110 to be shortened to fit inside the extents of motorcomponents 160 and 162 to minimize the overall length of drive station12. Further, encoder 150 is located within the axial extent of annularsleeve 118 of housing 114. Thus, drive station 12 has a minimal overalllength.

Housing 114 provides support of rotor 110 through bearing 126, acts as asealing diameter, houses and positions motor component 62, and pilotsend cap 136. End cap 136 provides support of rotor 110 through bearing140, acts as a sealing diameter, houses and captures encoder 150, andprovides a connection 166 for servo cable receptacles. To minimize theoverall length of drive station 12, end cap 136 fits inside annularsleeve 118 and motor components 160 and 162.

Thus since the invention disclosed herein may be embodied in otherspecific forms without departing from the spirit or generalcharacteristics thereof, some of which forms have been indicated, theembodiments described herein are to be considered in all respectsillustrative and not restrictive. The scope of the invention is to beindicated by the appended claims, rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are intended to be embraced therein.

The invention claimed is:
 1. Motion control apparatus comprising, incombination: a case including a planar annular disc and an annular wallextending from the planar annular disc and having a free end; an output;a bearing rotatably mounting the output to the case about an axis andwithin the annular wall extending axially with respect to the axis fromthe planar annular disc, wherein the bearing includes an inner race andan outer race rotatable relative to the inner race, with the inner raceintermediate the axis and the outer race, with the output removablyabutting with the outer race; a drive station mounted to the case androtating the output, with the output including a cylindrical flangehaving outer and inner diameters; a first annular seal located betweenthe case and the inner diameter of the output; a second annular seallocated between the annular wall of the case and the outer diameter ofthe output, wherein the case further includes an enclosure having apanel integrally connected to the annular wall and extending radiallyrelative to the axis outward opposite to the output, a top formed withthe panel, and a lower opening defined by the panel opposite to the top,with the panel and the lower opening having cross sections perpendicularto the axis which are U-shaped, with the annular wall including a sideopening into the enclosure, with the planar annular disc including anarcuate cutout extending from the side opening, with the drive stationextending in the lower opening, the side opening and the arcuate cutoutand rotatably engaging with the output, with the drive station includinga housing, with the housing including an annular end and an annularsleeve; a rotor rotatably mounted inside the annular sleeve about adrive axis and rotatably engaging with the output, with the rotorterminating in a rotor axial extent along the drive axis from theannular end opposite to the output, with the annular sleeve extendingparallel to the drive axis from the annular end and terminating in asleeve end at a sleeve axial extent along the drive axis from theannular end opposite to the output, with the rotor axial extent beingless than the sleeve axial extent; an annular end cap secured to thesleeve end; a rotor bearing rotatably mounting the rotor inside theannular end cap at a bearing axial extent along the drive axis from theannular end opposite to the output, with the bearing axial extent lessthan the sleeve axial extent and generally equal to or less than therotor axial extent; an encoder received in the annular end cap andhaving an inner axial extent along the drive axis closest to the annularend, with the encoder rotational with the rotor; and a motor componentlocated concentrically to the rotor and between the annular end and theannular end cap and within the annular sleeve, with the rotor rotatableinside the motor component, with the annular end and the annular sleeveintegrally formed as a single unitary piece; wherein the case includes abearing cap of generally L-shaped cross sections and including anaxially extending portion extending axially with respect to the axis anda radially extending portion extending radially with respect to the axisoutwardly of the axially extending portion and terminating in an annularfree end, with the axially and radially extending portions of thebearing cap removably abutting with the inner race, with the firstannular seal located between the annular free end of the radiallyextending portion and the inner diameter of the output, with the planarannular disc, the annular wall and the enclosure being integrally formedas a single monolithic piece part, wherein the inner axial extent of theencoder is less than the sleeve axial extent, with the motor componenthaving a motor extent less than the sleeve axial extent along the driveaxis from the annular end opposite to the output and greater than therotor axial extent.
 2. Motion control apparatus comprising, incombination: a case including a planar annular disc and an annular wallextending from the planar annular disc and having a free end; an output;a bearing rotatably mounting the output to the case about an axis andwithin the annular wall extending axially from the planar annular disc,wherein the bearing includes an inner race and an outer race rotatablerelative to the inner race, with the inner race being intermediate theaxis and the outer race; a drive station mounted to the case androtating the output, with the output including a cylindrical flangehaving outer and inner diameters; a first annular seal located betweenthe case and the inner diameter of the output; and a second annular seallocated between the annular wall of the case and the outer diameter ofthe output, wherein the case includes a bearing cap of generallyL-shaped cross sections and including an axially extending portionextending parallel to the axis and a radially extending portionextending radially relative to the axis outwardly of the axiallyextending portion and terminating in an annular free end, with theaxially and radially extending portions of the bearing cap removablyabutting with the inner race, with the first annular seal locatedbetween the annular free end of the radially extending portion and theinner diameter of the output, and with the output removably abuttingwith the outer race.
 3. The motion control apparatus of claim 2, whereinthe output further includes an annular pilot recess on a lower surfacethereof, with the outer race of the bearing received in the annularpilot recess.
 4. The motion control apparatus of claim 3 furthercomprising, in combination: fasteners extending parallel to the axis andthrough the outer race of the bearing and secured to the output in theannular pilot recess, with the first annular seal supported on the outerrace of the bearing.
 5. The motion control apparatus of claim 2, whereinthe output further includes an outer driven gear extending parallel to,intermediate and spaced from the cylindrical flange and the planarannular disc, with the outer driven gear having a radial extent outwardof the cylindrical flange.
 6. The motion control apparatus of claim 2,wherein the cylindrical flange includes mounting holes extending axiallyfrom a top surface of the cylindrical flange and radially intermediatethe inner and outer diameters.
 7. The motion control apparatus of claim2, wherein the case further includes an enclosure having a panelintegrally connected to the annular wall and extending radially withrespect to the axis outward opposite to the output; a top integrallyformed with the panel; and a lower opening defined by the panel oppositeto the top, with the panel, the top and the lower opening having crosssections perpendicular to the axis which are U-shaped, with the annularwall including a side opening into the enclosure, with the planarannular disc including an arcuate cutout extending from the sideopening, with the drive station extending in the lower opening, the sideopening and the arcuate cutout and rotatably engaging with the output,with the planar annular disc, the annular wall and the enclosure beingintegrally formed as a single monolithic piece part.
 8. The motioncontrol apparatus of claim 2, with the drive station comprising ahousing, with the housing including an annular end and an annularsleeve; a rotor rotatably mounted inside the annular sleeve about adrive axis and rotatably engaging the output, with the rotor terminatingin a rotor axial extent along the drive axis from the annular endopposite to the output, with the annular sleeve extending parallel tothe drive axis from the annular end and terminating in a sleeve end at asleeve axial extent along the drive axis from the annular end oppositeto the output, with the rotor axial extent being less than the sleeveaxial extent; an annular end cap secured to the sleeve end; a rotorbearing rotatably mounting the rotor inside the annular end cap at abearing axial extent along the drive axis from the annular end oppositeto the output less than the sleeve axial extent and generally equal toor less than the rotor axial extent; an encoder received in the annularend cap and having an inner axial extent along the drive axis closest tothe annular end less than the sleeve axial extent, with the encoderrotationally related to the rotor; and a motor located concentrically tothe rotor and between the annular end and the annular end cap and withinthe annular sleeve, with the annular end and the annular sleeveintegrally formed as a single monolithic unitary piece.
 9. The motioncontrol apparatus of claim 8, wherein the annular end extends radiallyrelative to the axis outward of the annular sleeve to define a mountingflange, with mounting holes formed in the mounting flange ofnon-circular cross sections perpendicular to the rotor, with themounting holes located off center relative to the rotor.
 10. The motioncontrol apparatus of claim 8, further comprising a preload cap securedto the rotor intermediate the rotor and the encoder, with the rotorbearing sandwiched between the preload cap and the annular end cap. 11.The motion control apparatus of claim 2, wherein the outer race islocated intermediate the planar annular disc and the output, wherein thecylindrical flange of the output extends over the outer race, with theinner diameter spaced from the inner race, with the radially extendingportion extending over the inner race and spaced from the outer race,with the first annular seal extending over the inner and outer races.12. Motion control apparatus comprising, in combination: a caseincluding a planar annular disc and an annular wall extending from theplanar annular disc and having a free end; an output; a bearingrotatably mounting the output to the case about an axis and within theannular wall extending axially from the planar annular disc; a drivestation mounted to the case and rotating the output, with the outputincluding a cylindrical flange having outer and inner diameters; a firstannular seal located between the case and the inner diameter of theoutput; and a second annular seal located between the annular wall ofthe case and the outer diameter of the output; wherein the case includesa bearing cap of generally L-shaped cross sections and including anaxially extending portion extending parallel to the axis and a radiallyextending portion extending radially relative to the axis outwardly ofthe axially extending portion and terminating in an annular free end,with the first annular seal located between the annular free end of theradially extending portion and the inner diameter of the output, whereinthe planar annular disc extends parallel to but spaced from thecylindrical flange of the output, with the planar annular disc extendingradially with respect to the axis outward of an axially extendingannular protrusion terminating in an upper annular free end, with theaxially extending portion of the bearing cap abutting with the upperannular free end and extending parallel to the axis and from the axiallyextending annular protrusion, with the bearing abutting with the planarannular disc and the axially extending annular protrusion, with thebearing sandwiched between the radially extending portion of the bearingcap and the planar annular disc of the case.
 13. The motion controlapparatus of claim 12 further comprising fasteners extending parallel tothe axis and through the axially extending portion of the bearing capand secured in the axially extending annular protrusion.
 14. A motioncontrol apparatus comprising, in combination: a housing, with thehousing including an annular end and an annular sleeve; a rotorrotatably mounted inside the annular sleeve about a drive axis andhaving a rotor end configured to rotatably engage an output, with therotor terminating in a rotor axial extent along the drive axis from theannular end and opposite to the rotor end, with the annular sleeveextending parallel to the axis from the annular end and terminating in asleeve end at a sleeve axial extent along the drive axis from theannular end opposite to the rotor end, with the rotor axial extent beingless than the sleeve axial extent; an annular end cap secured to thesleeve end; a rotor bearing rotatably mounting the rotor inside theannular end cap at a bearing axial extent along the drive axis from theannular end opposite to the rotor end less than the sleeve axial extentand generally equal to or less than the rotor axial extent; an encoderreceived in the annular end cap and having an inner axial extent alongthe drive axis closest to the annular end, with the encoder rotationalwith the rotor; and a motor located concentrically to the rotor andbetween the annular end and the annular end cap and within the annularsleeve, with the annular end and the annular sleeve integrally formed asa single unitary piece, wherein the motor comprises a first motorcomponent secured to the annular sleeve and having a first motor extentalong the drive axis from the annular end opposite to the rotor end, anda second motor component secured to the rotor and having a second motorextent along the drive axis from the annular wall opposite to the rotorend generally at a same radial extent as the rotor axial extent; whereinthe inner axial extent of the encoder is less than the sleeve axialextent, with the first motor extent less than the sleeve axial extentand greater than the rotor axial extent.
 15. The motion controlapparatus of claim 14, wherein the annular end extends radially relativeto the axis outward of the annular sleeve to define a mounting flange,with mounting holes formed in the mounting flange of non-circular crosssections perpendicular to the rotor, with the mounting holes located offcenter relative to the rotor.
 16. The motion control apparatus of claim14, further comprising a preload cap secured to the rotor intermediatethe rotor and the encoder, with the rotor bearing sandwiched between thepreload cap and the annular end cap.
 17. The motion control apparatus ofclaim 14, further comprising a housing bearing, with the annular endincluding an inner axial opening having a flange extending radiallyrelative to the axis and inwardly therefrom, with the rotor including ashoulder defined on the rotor, with the housing bearing sandwichedbetween the rotor and the inner axial opening and between the shoulderand the flange, with the rotor including rollers circumferentiallyarranged to be supported by a pair of annular plates, with the rotor andpair of annular plates integrally formed as a single undivided unit.